Regulating system



Aug. 8, 1939. E LQSNYDER 2,169,033

' REGULATING SYSTEM Filed March 23, 1955 z' .2 Regulated Fig zrcul'a L 1%; 4 Raga/areal WITNESSES:

INVENTOR ran/(Z272. Snyder Patented Aug. 8, 1939 BEGULA'I'ING SYSTEM I Franklin L. Snyder, Sharon, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation-of Vania Pennsyl Application March 2a, 1935, sex-nu No. 12,540.

comma (or. 111-119) My invention relates to apparatus for adjusting the voltage of an alternating-current circuit and it has particular relation to regulating equipmentcapable of automatically effecting such adjust- 5 ment in a small numberoi steps when the voltage or other characteristic of the circuit deviates suiflciently from a desired value to require correction.

In present-day electrical distribution systems,

or consumption through relatively long feeder circuits. As the loading of such a'circult increases, the voltagedrop through tts impedance is similarly raised with the result that the receiving end voltage is much lower for heavy than for light values of loading. 'In many instances, the nature of the loadsupplied issuch that the resulting wide variation in voltage is, while of course undesirable, not objectionable to .the point I that further expenditure for feeder circuit regulators of the induction and other relatively expensive types is justiiied. m invention is directed to an improved type of automatic voltage adjuster-which, because of its low cost and extreme simplicity, can be practically applied in situations of the above-outlined type. 1

One object of my invention is to reduce the cost of equipment adapted toautomatically adjust in one or two steps the voltage of analternatingcurrent circuit. I

Another oblect of my invention is to provide an improved control system for such adjusting equipments. I

Aiurther object is to increase the reliability and reduce the frequency of operation of. the

equipments of. the type under consideration.

In practicing my invention, I te with the circuit to.be regulated, anauto or other transformer having a continuously energized primary winding and a two-section secondary winding which is capable of carrying the circuit load current. This secondary is arranged to be partially or whollyconne'cted in series with one of the circuit conductors upon the actuation of jcontrol apparatus respo e ve either to changes in the circuit, voltage or in the loadcui'rent. To eilect the described connection control without interrupting the regulated circuit load current, I utilize an especially magnetically-operated tap changer which determines the portion of the secondarypwlnding 'in active circuit connection. The new equipment may be duigned to effect either a one or atwo-step adjustse an invention no.

it is customary to supply energy to distant points objects and advantages thereof, will best be understood through the-following, description. of specific embodiments when taken in conjunction with the accompanying drawing, in which:

Figure 1 is a diagrammatic view of apparatus and circuits showing a preferred form of the automatic regulating system of my invention arranged to adjust in a single step the voltage of a single-phase feeder circuit;

Fig. 2 is a diagrammatic reproduction of a por- 10 tion of the system of Flg.-1 showing certain modiilcations in the booster-winding connections thereof;

Fig. 3 is a diagrammatic'view of a modification of the improved regulating system of my inven- 15 tion which is adapted to provide two steps of circuit-voltage adjustment; and I Fig. 4 is a diagrammatic reproduction of a portion of the systems oi Figs. 1 and 3 showing how the primary relay may be connected to respond 20 to load current rather than to circuit voltage.

Referring to the drawing, and particularly to Fig. 1 thereof, the voltage-adjusting means of my invention are there diagrammatically represented.

as comprising a regulating transformer having a 25- .primary winding i2 adapted to receive energizetion from the voltage of a power-supply circuit it -l5 and a secondary winding I S-l1 adapted to be connected in series with one of the conductors of a circuit l4l 8 the voltage of which is to be regulated. Control of the portion of this secondary winding in this active connection is effected by a contactor 2B which, through a secondary relay 22, is controlled by a primary relay 24, the actuating winding 26 of which is energized by a measure of the voltage of supply circuit iQ-IB derived from an auxiliary winding 28 associated with the main transformer.

As long as the'supply-circuit voltage remains at or close to the desired value the several devices 40 illustrated occupy the positions shown and powercircuit conductors l5 and it remain directly interconnected by member L'of contactor 20. Under these circumstances 1 the regulated circuit voltage is the same as i i-ll. 7

When, however, thevoltage oi the supply circuit decreases to a predetermined value, for-example, to of normal, relay 24 engages a movable contact membe II with a stationary-mem- 50 her R; thereby completing for the actuating winding 32 of secondary relay 2!, an energizing circuit which extends from the lower terminal of I control supply winding 20 throughconductor 34. relay contacts II and R, conductor II, the relay 6 that of the supply circuit 45 for the actuating 4| ofthe main contactor 20, an energizing circuit which extends from the lower terminal of control supply winding 28 through conductor 4!, the winding", the relay contact 38, and conductors 42 and 35 back to the upper terminal of winding 28. Thus energized, the contactor 20 biases its contact members upwardly interrupting, by.

means of member L, the direct connection between circuit conductors l5 and I8 and establishing, by means of member R, a direct connection between the lower end of booster winding Ii-l'i and regulated circuit conductor 68.

Following the opening of contact member L and preceding the closing of member R, the power circuit current flows through a path which ineludes the upper section ii of the booster winding'and the winding 45 of a preventive auto transformer. The preventive autoflt prevents an interruption in the circuit between theconfor a single-step equipment is preferably of the i order of from 5% to 16%. The connections of the secondary windings l6-'-l'| shown in Fig. 1 provide a maximum value. In case it is desired to cut this value to double the current carrying capacity of the equipment, this may be done by resorting to the parallel form of connection depicted in Fig. 2. It willbe noted that in this connection, each of the winding sections l6 and i1 is provided with a mid-tap by means of which the corresponding haves of the two windings are connected in parallel circuit relation. A similar change is made in the interconnection of the two halves of the preventive auto-transformer winding 86.

In many situations, it is desirable'to provide more than one step of voltage adjustment and for these the equipment depicted in Fig. 3 is particularly well suited. Basically, this system is ductors i5 and it during operationoi the contactor 20 from one circuit closing position to the other and serves as a reactor to prevent high circulating current through the local circuit supplied with voltage portions is or I! of the secondary win i through the closed contact member L or R, thus preventing the short c cult current that would exist if the conductor i8 were directly connected to the midpoint between the secondary winding portions I6 and i1. of the arrangement shown,'the tap-changingoperation just described is made withoutv interrupting the reguiated-.-cirfrom the one or the other tions.

cuit current and the voltage impressed upon this circuit during the transition period is of a value. intermediate that determined by the illustrated un-actuated position of the main contactor 2Q and the described actuated position to which it is caused to move after persistence for a proper time of a primary relay control impulse.

This voltage-boosting adjustment of the equipment is maintained until the voltage of the supply circuit again increases to a certain value. for example, to 98% of normal, at which time thecontacts 30 and R of theprimary relay 24 are caused to separate. VA compounding coil 46 associatedwith this relay makes possible a separation of the contacts'at-a higher value of voltage than that whicheflfected their ori engagement. This disengagement deenergim the ting winding of secondary relay 22, allowgthisrelamafteratimedelusimilartothat previously mentioned, to move itscontact member 38 downwardly, thereby interrupting the acmentioned time delay tuating circuit of the again move downwardly to theillustrated'posh tion, member R interrupting therapies connec- .tion of booster li-ll, betweenpower circuit conductors I and II and member L re storing a direct connection betvrreenthme two conductors. In this normal position or the'seve'ral devices, the. voltage of regulated |4|l.is the same as circuit that oi 'circuit In practice, the magnitude of the' the same as that of Fig. l with the exception that it is adapted to provide two steps of voltage adjustment. Associated with the booster windings iB-i| are two main or tap changing connectors in half and at thesame time 88 and 59 which through a pair of secondary relays 52 and 5d are controlled by the primary relay or contact making voltmeter 24' in accordance with deviations in the voltage of supply circuit idiE.

In operation of the system of Fig. 3 when the supply circuit voltage is of the desired or-normal value, the contact member 30 of the primary relay 26' occupies the disengaged or neutral posi- 'tion' shown and both of the named main contactors occupy the illustrated unactua'ted posi- For such condition there is completed by means of contact memberfit and 58 carried by these contactorsa circuit through which the upsection it of the transformer secondary winding is series-connected, between power circuit conductors l5 and i8. Winding section is thus introduces into theregulated circuit an inexample, to 95% of normal, primary relay 24 engages contact members 30 and R, thereby "competing for secondary relay '56 an actuating 'circuit which extends from the lower terminal or control supply winding 28, through conductor 34, contact members 30 and R of relay 2%, conductor 35, the winding 60 of secondary relay 54 and conductor 36 back to the. upper terminal of control supp y winding 28. Thus energized, the relay 54 predetermined time which may vary from ten to ninety' seconds, its contactmembers 62 upwardly thereby completing for main contactor 48 an acid-IE decreases to a predetermined value, for

moves, after a tuating circuit which extends from the lower terminal of control suppLv winding 28 through conductor 4|, the actuating winding 84 of contactor 48, a' switch blade ii ycontact member 62 of secondary relay 54 and: conductor 38 back to-the upperterminal of control supply winding 28.

'lhusenergiud, conductor 48 biases its contact members upwardly interrupting at member 56 the direct connection between the lower end of booster winding l6 and regulated circuit con-' 'ductor II and establisbingby' means of member 1}" a similar connection between the lower end of booster winding l 'l andthesame regulated circuit conductor; Following the opening of member. and preceding the closing. of member in", the power circuit current is carried by the preventive mite-transformer winding .44.

completion ofthis described operation V I I v and conductors 13 in turn restores the contact members of maincontactor 48 to the positions shown in which only booster winding I6 is in active connection withthe regulated circuit. The indicated difference between the contact engagement and disengagement voltage values 01' primary relay 24' is ef-' fected through the utili tion of the compounding coils 46'.

In a similar mannen in the event that the voltage of supply circuit i4-i5 rises to a predetermined value, for example to 105% of normal, primary relay 24' engages contact members 80 and L, thereby completing for secondary relay 52 an actuating circuit which extends from the lower terminal of control supply winding 28 through conductor 34, relay contact members 30 and L, conductor 86, the winding 88 of secondary. relay 52 and conductors i9 and 38,-back to the upper terminal of control supply winding 28.

Thus energized, relay 52 biases, after a predetermined time, its contact member l0 upwardly thereby completing for main contactor 58 an 'actuatingcircuit which extends from the lower terminal of control supply winding 28 through conductor 4|, the actuating winding 12 vof contactor 58, contact member 18 of relay 52 terminal-of control supply winding 28.

Thus energized, this contactor biases its contact members upwardly, interrupting at member 58 the connections between the lower end of booster winding section It and regulated circuit conductor l8 and establishing by member L" a direct connection between supply source conductor i5 and the same regulated circuit conductor) By virtue of this direct connection the regulated circuit voltage is reduced to the same value as that of the supply circuit, no portion of the booster winding lG-H then being in active circuit connection. 1 This low-voltage adjustment of the regulated circuit continues until the supply circuit voltage decreases to a certain value, for example to 102% of normal, at which time primary relay 24' separates contact members 88 and L, thereby allowing, after a time delay, secondary relay 52 to move to-the unactuated'position illustrated. As a result, main contactor also moves to the un-- actuatedposition' and restores booster winding section It into active connection with the regu lated circuit. This introduces into the circuit the normal or intermediate value of boosting voltage.

when it is desired to by-pass the booster winding lB-il, as in taking the booster out of service, the switch, comprising blade previously mentioned and a second blade 14, is thrown downwardly causing the booster to go to the nonboost position and stay there until the switch is again returned to the normal position illustrated. In the downward position blade 68 permanently opens the actuating circuit for voltage-raising contactor and blade," completes the actuating circuit for voltage-decreasing contactor 88.

Instead of utilizing changes in supply circuit which time primary and 36 .back to the upper voltage to actuate the prima'ry relay, variations 7 in the load current of the regulated circuit may also be employed One preferred manner of eflecting such modified control is indicated in Fig. .4 in which'the actuating winding 26 of the primary relay 24" is connected with a current transformer I5 associated with the regulated circuit conductor l4. As the circuit loading'increases, the primary relay is caused to bias contact member 38 downwardly into engagement with the contact member L, thereby efl'ecting a corrective increase in the amount of boosting voltage. Similarly, when the circuit loading decreases below a given value, contact member 88,

is biased upwardly into engagement with member R', thereby similarly'eflecting acorrective decrease in themagnitude of the boosting voltage. Although I have shown and described certain specific embodimentsof my invntion,I- am fully aware that many modifications thereof are Dos-- sible. My invention, therefore, is not to-be'restricted except insofar as is necessitated by the prior art and by the scope of the appended claims.

I claim as my invention:

l. Voltage-adjusting means for an electrical circuit comprising a transformer having a sec- ."ondary winding adapted to carry the circuit load current and a primary winding energized by the circuit voltage, a contactor having two circuit closing positions and adapted in one circuit 0105- ing'position to connect said secondary winding in series-circuit relation with the circuit and in a second circuit closing position to interrupt and by-pass this connection, a primary relay, sensi-, tive to changes inan electrical characteristic of the circuit, for controlling actuation of said con-'- tactor from'one to the other of the two circuit closing positions above named, and: an impedor adapted'to carry the circuit load current during the period ofcontactor positional changeand bypassed'by saidcontactor in either of its circuit closing positions. r

2. Voltage-adjusting meansfor-an electrical current and a primary. winding energized by the circuit voltage, a contactor adapted inone circuit closing position to connect said secondary windingxin series-circuitl relation with the cir-- cut and in a second circuit closing positionto" interrupt and by-pass this connection, a primary Y relay, sensitive to changesinanelectrical chari circuitcornprising a transformer having a secondary winding adapted to carry the circuit load acteristic .of the circuit, for controlling r actuation of said contactor from one vftoithe otherof the .twor-circuit closing .positions..above named,.and' a preventiveauto-transformer winding bypassed :by said contactor when in either :of 'its circuit closing positions and adapted to carry the circuit load current during the period of contactor positional change from one to the other of its circuit closing positions. 9

3. A voltage-controlling regulator for an electrical circuit comprising a transformer having a secondary winding and a primary winding energlzably connected across the circuit, a contactor adapted in one position to connect said secondary winding in series-circuit relation with the circuit and in a second position to interrupt and by-pass this connection, a preventive autotransformer winding permanently interconnected between said secondary winding and the regulated circuit to carry the circuit load current only'during the period of contactor positional, change from one to the other of the two abovenamed positions, and a primary y. sensitive 4 to changes inan electrical characteristic of the circuit, for controlling actuation of said contactor from one to the other of the two above-named positions. I a

' actuation of said two contactors.

I 4. A voltage-controlling regulator for an elec-- trical circuit comprising a transformer having a secondary winding and a primary winding energizably connected across thexcircuit, a comtactor having two circuit closing positions and adapted in one circuit closing position to connect said secondary winding in series-circnit re-. lation with the circuit and in the othercricuit closing position to' interrupt and by-pass. this connection, a preventive auto-transformer winding connected "between an intermediate point along said secondary winding and the regulated .and a secondary winding having two series-con nected'sections the end oioneoi which is connected with one of the conductors of the powersource side of the circuit, a preventive autotransformer winding connected between the other end of said secondary winding section and the corresponding conductor of the regulated side of the circuit thereby placing the two windings last named in series-circuit connective relation with said circuit, a contactor adapted to shunt said connectio a. second contactor adapted to connect the free end of the other of saidsecondary winding sections with the reulated circuit conductor above named, and a primary relay, sensitive'to changes in an electrical characteristic of the circuit, for selectively controlling 6. Voltage-adjusting means for anelectrical circuit comprising a transformer having a primary winding energized by the circuit voltage.

and asecondary winding having two series-connected sections the end of one of which is con! nected with one of the conductors of the power-- source side- .of the circuit, a preventive autotransformer winding connected between the other end of said secondary winding section and the corresponding conductor. of the regulated side of the circuit thereby placing the two windings last named in series-circuit connective relation with said .circuitya contactor adapted to shunt said connection. asecond contactor adapted to 'grees to the rising connect the free end of the other of said secondary winding sections with the regulated circuit conductors above named, means whereby an occupation of the umactuated position by both contactors establishes a shunt connection around said preventive auto-transformer winding, and a primary relay, sensitive to changes in an electrical characteristic of the-circuit, for selectively controlling actuation of said two contactors.

7. A voltage-controlling regulator for an electrical circuit comprising a transformer having a secondary winding and a primary winding energizably connected across the circuit, a switch adapted in-one position to connect said secondary winding in series circuit relation with the circuit and m a second position to interrupt'this connection and bypass said secondary winding, a primary relay sensitive to changes in an electrical characteristic of the circuit for controlling actuation .of said switch vfrom one to the other of the two above named positions, and means 7 for rendering said relay sensitive in difiering de and falling directions of change in the regulated characteristic.

8. A voltage-controlling regulator for an electrical circuit comprising a transformer having a secondary winding and a primary winding energizably connected across the circuit, a two'- position electro-magnetically operated contactor adapted in its actuated position to connect said secondary winding in series circuit relation with the circuit and in its deactuated position to interrupt this connection and bypass said secondary winding, a primary relay sensitive to changes in an electrical characteristic of the circuit for controlling actuation of said contactor from one to the other 'of the two above named positions, and means for rendering-said relay sensitive indiffering degrees to the rising and falling directions of change in the regulated characteristic.

9. A voltage-controlling regulator for an electrical circuit comprising a transformer having a secondary and a primary winding energizably connected across the circuit, a switch adapted in one position to connect said secondary winding in series circuit relation with the circuit and in a second position to interrupt this connection and bypass said secondary winding, a normally substantially non-current carrying inductive winding connected between an intermediate point along said secondary winding and the regulated clrcuitinsuch manner that it carries through a portion of said secondary winding the circuit load currentduring the period ofswitch pomtional change, anda primary relay for controlling actuation of said switch from one to the other of the two abovev named positions.

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